# -*- coding: utf-8 -*-
#
# Copyright © 2009-2010 Pierre Raybaut
# Licensed under the terms of the MIT License
# (see spyderlib/__init__.py for details)

"""Shell widgets: base, python and terminal"""

# pylint: disable=C0103
# pylint: disable=R0903
# pylint: disable=R0911
# pylint: disable=R0201

# Standard library imports
import keyword
import locale
import os
import os.path as osp
import re
import sys
import time

# Third party imports
from qtpy.compat import getsavefilename
from qtpy.QtCore import Property, QCoreApplication, Qt, QTimer, Signal, Slot
from qtpy.QtGui import QKeySequence, QTextCharFormat, QTextCursor
from qtpy.QtWidgets import QApplication, QMenu, QMessageBox, QToolTip

# Local import
from spyderlib.config.base import _, DEBUG, get_conf_path, STDERR
from spyderlib.config.gui import create_shortcut, get_shortcut, new_shortcut
from spyderlib.config.main import CONF
from spyderlib.py3compat import (builtins, is_string, is_text_string,
                                 PY3, to_text_string)
from spyderlib.utils import encoding
from spyderlib.utils import icon_manager as ima
from spyderlib.utils.qthelpers import (add_actions, create_action, keybinding,
                                       restore_keyevent)
from spyderlib.widgets.arraybuilder import SHORTCUT_INLINE, SHORTCUT_TABLE
from spyderlib.widgets.mixins import (GetHelpMixin, SaveHistoryMixin,
                                      TracebackLinksMixin)
from spyderlib.widgets.sourcecode.base import ConsoleBaseWidget


class ShellBaseWidget(ConsoleBaseWidget, SaveHistoryMixin):
    """
    Shell base widget
    """
    
    redirect_stdio = Signal(bool)
    sig_keyboard_interrupt = Signal()
    execute = Signal(str)
    append_to_history = Signal(str, str)
    
    def __init__(self, parent, history_filename, profile=False):
        """
        parent : specifies the parent widget
        """
        ConsoleBaseWidget.__init__(self, parent)
        SaveHistoryMixin.__init__(self)
                
        # Prompt position: tuple (line, index)
        self.current_prompt_pos = None
        self.new_input_line = True
        
        # History
        self.histidx = None
        self.hist_wholeline = False
        assert is_text_string(history_filename)
        self.history_filename = history_filename
        self.history = self.load_history()
        
        # Session
        self.historylog_filename = CONF.get('main', 'historylog_filename',
                                            get_conf_path('history.log'))
        
        # Context menu
        self.menu = None
        self.setup_context_menu()

        # Simple profiling test
        self.profile = profile
        
        # Buffer to increase performance of write/flush operations
        self.__buffer = []
        self.__timestamp = 0.0
        self.__flushtimer = QTimer(self)
        self.__flushtimer.setSingleShot(True)
        self.__flushtimer.timeout.connect(self.flush)

        # Give focus to widget
        self.setFocus()

        # Cursor width
        self.setCursorWidth( CONF.get('main', 'cursor/width') )

    def toggle_wrap_mode(self, enable):
        """Enable/disable wrap mode"""
        self.set_wrap_mode('character' if enable else None)

    def set_font(self, font):
        """Set shell styles font"""
        self.setFont(font)
        self.set_pythonshell_font(font)
        cursor = self.textCursor()
        cursor.select(QTextCursor.Document)
        charformat = QTextCharFormat()
        charformat.setFontFamily(font.family())
        charformat.setFontPointSize(font.pointSize())
        cursor.mergeCharFormat(charformat)


    #------ Context menu
    def setup_context_menu(self):
        """Setup shell context menu"""
        self.menu = QMenu(self)
        self.cut_action = create_action(self, _("Cut"),
                                        shortcut=keybinding('Cut'),
                                        icon=ima.icon('editcut'),
                                        triggered=self.cut)
        self.copy_action = create_action(self, _("Copy"),
                                         shortcut=keybinding('Copy'),
                                         icon=ima.icon('editcopy'),
                                         triggered=self.copy)
        paste_action = create_action(self, _("Paste"),
                                     shortcut=keybinding('Paste'),
                                     icon=ima.icon('editpaste'),
                                     triggered=self.paste)
        save_action = create_action(self, _("Save history log..."),
                                    icon=ima.icon('filesave'),
                                    tip=_("Save current history log (i.e. all "
                                          "inputs and outputs) in a text file"),
                                    triggered=self.save_historylog)
        self.delete_action = create_action(self, _("Delete"),
                                    shortcut=keybinding('Delete'),
                                    icon=ima.icon('editdelete'),
                                    triggered=self.delete)
        selectall_action = create_action(self, _("Select All"),
                                    shortcut=keybinding('SelectAll'),
                                    icon=ima.icon('selectall'),
                                    triggered=self.selectAll)
        add_actions(self.menu, (self.cut_action, self.copy_action,
                                paste_action, self.delete_action, None,
                                selectall_action, None, save_action) )
          
    def contextMenuEvent(self, event):
        """Reimplement Qt method"""
        state = self.has_selected_text()
        self.copy_action.setEnabled(state)
        self.cut_action.setEnabled(state)
        self.delete_action.setEnabled(state)
        self.menu.popup(event.globalPos())
        event.accept()        
        
        
    #------ Input buffer
    def get_current_line_from_cursor(self):
        return self.get_text('cursor', 'eof')
    
    def _select_input(self):
        """Select current line (without selecting console prompt)"""
        line, index = self.get_position('eof')
        if self.current_prompt_pos is None:
            pline, pindex = line, index
        else:
            pline, pindex = self.current_prompt_pos
        self.setSelection(pline, pindex, line, index)

    @Slot()
    def clear_line(self):
        """Clear current line (without clearing console prompt)"""
        if self.current_prompt_pos is not None:
            self.remove_text(self.current_prompt_pos, 'eof')

    @Slot()
    def clear_terminal(self):
        """
        Clear terminal window
        Child classes reimplement this method to write prompt
        """
        self.clear()

    # The buffer being edited
    def _set_input_buffer(self, text):
        """Set input buffer"""
        if self.current_prompt_pos is not None:
            self.replace_text(self.current_prompt_pos, 'eol', text)
        else:
            self.insert(text)
        self.set_cursor_position('eof')

    def _get_input_buffer(self):
        """Return input buffer"""
        input_buffer = ''
        if self.current_prompt_pos is not None:
            input_buffer = self.get_text(self.current_prompt_pos, 'eol')
            input_buffer = input_buffer.replace(os.linesep, '\n')
        return input_buffer

    input_buffer = Property("QString", _get_input_buffer, _set_input_buffer)
        
        
    #------ Prompt
    def new_prompt(self, prompt):
        """
        Print a new prompt and save its (line, index) position
        """
        if self.get_cursor_line_column()[1] != 0:
            self.write('\n')
        self.write(prompt, prompt=True)
        # now we update our cursor giving end of prompt
        self.current_prompt_pos = self.get_position('cursor')
        self.ensureCursorVisible()
        self.new_input_line = False
        
    def check_selection(self):
        """
        Check if selected text is r/w,
        otherwise remove read-only parts of selection
        """
        if self.current_prompt_pos is None:
            self.set_cursor_position('eof')
        else:
            self.truncate_selection(self.current_prompt_pos)
        
        
    #------ Copy / Keyboard interrupt
    @Slot()
    def copy(self):
        """Copy text to clipboard... or keyboard interrupt"""
        if self.has_selected_text():
            ConsoleBaseWidget.copy(self)
        elif not sys.platform == 'darwin':
            self.interrupt()

    def interrupt(self):
        """Keyboard interrupt"""
        self.sig_keyboard_interrupt.emit()

    @Slot()
    def cut(self):
        """Cut text"""
        self.check_selection()
        if self.has_selected_text():
            ConsoleBaseWidget.cut(self)

    @Slot()
    def delete(self):
        """Remove selected text"""
        self.check_selection()
        if self.has_selected_text():
            ConsoleBaseWidget.remove_selected_text(self)

    @Slot()
    def save_historylog(self):
        """Save current history log (all text in console)"""
        title = _("Save history log")
        self.redirect_stdio.emit(False)
        filename, _selfilter = getsavefilename(self, title,
                    self.historylog_filename, "%s (*.log)" % _("History logs"))
        self.redirect_stdio.emit(True)
        if filename:
            filename = osp.normpath(filename)
            try:
                encoding.write(to_text_string(self.get_text_with_eol()),
                               filename)
                self.historylog_filename = filename
                CONF.set('main', 'historylog_filename', filename)
            except EnvironmentError as error:
                QMessageBox.critical(self, title,
                                     _("<b>Unable to save file '%s'</b>"
                                       "<br><br>Error message:<br>%s"
                                       ) % (osp.basename(filename),
                                            to_text_string(error)))
        
        
    #------ Basic keypress event handler
    def on_enter(self, command):
        """on_enter"""
        self.execute_command(command)
        
    def execute_command(self, command):
        self.execute.emit(command)
        self.add_to_history(command)
        self.new_input_line = True
        
    def on_new_line(self):
        """On new input line"""
        self.set_cursor_position('eof')
        self.current_prompt_pos = self.get_position('cursor')
        self.new_input_line = False

    @Slot()
    def paste(self):
        """Reimplemented slot to handle multiline paste action"""
        if self.new_input_line:
            self.on_new_line()
        ConsoleBaseWidget.paste(self)
        
    def keyPressEvent(self, event):
        """
        Reimplement Qt Method
        Basic keypress event handler
        (reimplemented in InternalShell to add more sophisticated features)
        """
        if self.preprocess_keyevent(event):
            # Event was accepted in self.preprocess_keyevent
            return
        self.postprocess_keyevent(event)
        
    def preprocess_keyevent(self, event):
        """Pre-process keypress event:
        return True if event is accepted, false otherwise"""
        # Copy must be done first to be able to copy read-only text parts
        # (otherwise, right below, we would remove selection
        #  if not on current line)
        ctrl = event.modifiers() & Qt.ControlModifier
        meta = event.modifiers() & Qt.MetaModifier    # meta=ctrl in OSX
        if event.key() == Qt.Key_C and \
          ((Qt.MetaModifier | Qt.ControlModifier) & event.modifiers()):
            if meta and sys.platform == 'darwin':
                self.interrupt()
            elif ctrl:
                self.copy()
            event.accept()
            return True
        
        if self.new_input_line and ( len(event.text()) or event.key() in \
           (Qt.Key_Up, Qt.Key_Down, Qt.Key_Left, Qt.Key_Right) ):
            self.on_new_line()
        
        return False
        
    def postprocess_keyevent(self, event):
        """Post-process keypress event:
        in InternalShell, this is method is called when shell is ready"""
        event, text, key, ctrl, shift = restore_keyevent(event)
        
        # Is cursor on the last line? and after prompt?
        if len(text):
            #XXX: Shouldn't it be: `if len(unicode(text).strip(os.linesep))` ?
            if self.has_selected_text():
                self.check_selection()
            self.restrict_cursor_position(self.current_prompt_pos, 'eof')
            
        cursor_position = self.get_position('cursor')

        if key in (Qt.Key_Return, Qt.Key_Enter):
            if self.is_cursor_on_last_line():
                self._key_enter()
            # add and run selection
            else:
                self.insert_text(self.get_selected_text(), at_end=True)
            
        elif key == Qt.Key_Insert and not shift and not ctrl:
            self.setOverwriteMode(not self.overwriteMode())
            
        elif key == Qt.Key_Delete:
            if self.has_selected_text():
                self.check_selection()
                self.remove_selected_text()
            elif self.is_cursor_on_last_line():
                self.stdkey_clear()
            
        elif key == Qt.Key_Backspace:
            self._key_backspace(cursor_position)
            
        elif key == Qt.Key_Tab:
            self._key_tab()
            
        elif key == Qt.Key_Space and ctrl:
            self._key_ctrl_space()

        elif key == Qt.Key_Left:
            if self.current_prompt_pos == cursor_position:
                # Avoid moving cursor on prompt
                return
            method = self.extend_selection_to_next if shift \
                     else self.move_cursor_to_next
            method('word' if ctrl else 'character', direction='left')
                
        elif key == Qt.Key_Right:
            if self.is_cursor_at_end():
                return
            method = self.extend_selection_to_next if shift \
                     else self.move_cursor_to_next
            method('word' if ctrl else 'character', direction='right')

        elif (key == Qt.Key_Home) or ((key == Qt.Key_Up) and ctrl):
            self._key_home(shift, ctrl)

        elif (key == Qt.Key_End) or ((key == Qt.Key_Down) and ctrl):
            self._key_end(shift, ctrl)

        elif key == Qt.Key_Up:
            if not self.is_cursor_on_last_line():
                self.set_cursor_position('eof')
            y_cursor = self.get_coordinates(cursor_position)[1]
            y_prompt = self.get_coordinates(self.current_prompt_pos)[1]
            if y_cursor > y_prompt:
                self.stdkey_up(shift)
            else:
                self.browse_history(backward=True)
                
        elif key == Qt.Key_Down:
            if not self.is_cursor_on_last_line():
                self.set_cursor_position('eof')
            y_cursor = self.get_coordinates(cursor_position)[1]
            y_end = self.get_coordinates('eol')[1]
            if y_cursor < y_end:
                self.stdkey_down(shift)
            else:
                self.browse_history(backward=False)
            
        elif key in (Qt.Key_PageUp, Qt.Key_PageDown):
            #XXX: Find a way to do this programmatically instead of calling
            # widget keyhandler (this won't work if the *event* is coming from
            # the event queue - i.e. if the busy buffer is ever implemented)
            ConsoleBaseWidget.keyPressEvent(self, event)

        elif key == Qt.Key_Escape and shift:
            self.clear_line()

        elif key == Qt.Key_Escape:
            self._key_escape()
                
        elif key == Qt.Key_L and ctrl:
            self.clear_terminal()
            
        elif key == Qt.Key_V and ctrl:
            self.paste()
            
        elif key == Qt.Key_X and ctrl:
            self.cut()
            
        elif key == Qt.Key_Z and ctrl:
            self.undo()
            
        elif key == Qt.Key_Y and ctrl:
            self.redo()
            
        elif key == Qt.Key_A and ctrl:
            self.selectAll()
                
        elif key == Qt.Key_Question and not self.has_selected_text():
            self._key_question(text)
            
        elif key == Qt.Key_ParenLeft and not self.has_selected_text():
            self._key_parenleft(text)
            
        elif key == Qt.Key_Period and not self.has_selected_text():
            self._key_period(text)

        elif len(text) and not self.isReadOnly():
            self.hist_wholeline = False
            self.insert_text(text)
            self._key_other(text)
                
        else:
            # Let the parent widget handle the key press event
            ConsoleBaseWidget.keyPressEvent(self, event)
            
                
    #------ Key handlers
    def _key_enter(self):
        command = self.input_buffer
        self.insert_text('\n', at_end=True)
        self.on_enter(command)
        self.flush()
    def _key_other(self, text):
        raise NotImplementedError
    def _key_backspace(self, cursor_position):
        raise NotImplementedError
    def _key_tab(self):
        raise NotImplementedError
    def _key_ctrl_space(self):
        raise NotImplementedError
    def _key_home(self, shift, ctrl):
        if self.is_cursor_on_last_line():
            self.stdkey_home(shift, ctrl, self.current_prompt_pos)
    def _key_end(self, shift, ctrl):
        if self.is_cursor_on_last_line():
            self.stdkey_end(shift, ctrl)
    def _key_pageup(self):
        raise NotImplementedError
    def _key_pagedown(self):
        raise NotImplementedError
    def _key_escape(self):
        raise NotImplementedError
    def _key_question(self, text):
        raise NotImplementedError
    def _key_parenleft(self, text):
        raise NotImplementedError
    def _key_period(self, text):
        raise NotImplementedError

        
    #------ History Management
    def load_history(self):
        """Load history from a .py file in user home directory"""
        if osp.isfile(self.history_filename):
            rawhistory, _ = encoding.readlines(self.history_filename)
            rawhistory = [line.replace('\n', '') for line in rawhistory]
            if rawhistory[1] != self.INITHISTORY[1]:
                rawhistory[1] = self.INITHISTORY[1]
        else:
            rawhistory = self.INITHISTORY
        history = [line for line in rawhistory \
                   if line and not line.startswith('#')]

        # Truncating history to X entries:
        while len(history) >= CONF.get('historylog', 'max_entries'):
            del history[0]
            while rawhistory[0].startswith('#'):
                del rawhistory[0]
            del rawhistory[0]
        # Saving truncated history:
        encoding.writelines(rawhistory, self.history_filename)
        return history
        
    def browse_history(self, backward):
        """Browse history"""
        if self.is_cursor_before('eol') and self.hist_wholeline:
            self.hist_wholeline = False
        tocursor = self.get_current_line_to_cursor()
        text, self.histidx = self.__find_in_history(tocursor,
                                                    self.histidx, backward)
        if text is not None:
            if self.hist_wholeline:
                self.clear_line()
                self.insert_text(text)
            else:
                cursor_position = self.get_position('cursor')
                # Removing text from cursor to the end of the line
                self.remove_text('cursor', 'eol')
                # Inserting history text
                self.insert_text(text)
                self.set_cursor_position(cursor_position)

    def __find_in_history(self, tocursor, start_idx, backward):
        """Find text 'tocursor' in history, from index 'start_idx'"""
        if start_idx is None:
            start_idx = len(self.history)
        # Finding text in history
        step = -1 if backward else 1
        idx = start_idx
        if len(tocursor) == 0 or self.hist_wholeline:
            idx += step
            if idx >= len(self.history) or len(self.history) == 0:
                return "", len(self.history)
            elif idx < 0:
                idx = 0
            self.hist_wholeline = True
            return self.history[idx], idx
        else:
            for index in range(len(self.history)):
                idx = (start_idx+step*(index+1)) % len(self.history)
                entry = self.history[idx]
                if entry.startswith(tocursor):
                    return entry[len(tocursor):], idx
            else:
                return None, start_idx
    
    
    #------ Simulation standards input/output
    def write_error(self, text):
        """Simulate stderr"""
        self.flush()
        self.write(text, flush=True, error=True)
        if DEBUG:
            STDERR.write(text)

    def write(self, text, flush=False, error=False, prompt=False):
        """Simulate stdout and stderr"""
        if prompt:
            self.flush()
        if not is_string(text):
            # This test is useful to discriminate QStrings from decoded str
            text = to_text_string(text)
        self.__buffer.append(text)
        ts = time.time()
        if flush or prompt:
            self.flush(error=error, prompt=prompt)
        elif ts - self.__timestamp > 0.05:
            self.flush(error=error)
            self.__timestamp = ts
            # Timer to flush strings cached by last write() operation in series
            self.__flushtimer.start(50)

    def flush(self, error=False, prompt=False):
        """Flush buffer, write text to console"""
        # Fix for Issue 2452 
        if PY3:
            try:
                text = "".join(self.__buffer)
            except TypeError:
                text = b"".join(self.__buffer)
                try:
                    text = text.decode( locale.getdefaultlocale()[1] )
                except:
                    pass
        else:
            text = "".join(self.__buffer)

        self.__buffer = []
        self.insert_text(text, at_end=True, error=error, prompt=prompt)
        QCoreApplication.processEvents()
        self.repaint()
        # Clear input buffer:
        self.new_input_line = True


    #------ Text Insertion
    def insert_text(self, text, at_end=False, error=False, prompt=False):
        """
        Insert text at the current cursor position
        or at the end of the command line
        """
        if at_end:
            # Insert text at the end of the command line
            self.append_text_to_shell(text, error, prompt)
        else:
            # Insert text at current cursor position
            ConsoleBaseWidget.insert_text(self, text)

            
    #------ Re-implemented Qt Methods
    def focusNextPrevChild(self, next):
        """
        Reimplemented to stop Tab moving to the next window
        """
        if next:
            return False
        return ConsoleBaseWidget.focusNextPrevChild(self, next)

    
    #------ Drag and drop
    def dragEnterEvent(self, event):
        """Drag and Drop - Enter event"""
        event.setAccepted(event.mimeData().hasFormat("text/plain"))

    def dragMoveEvent(self, event):
        """Drag and Drop - Move event"""
        if (event.mimeData().hasFormat("text/plain")):
            event.setDropAction(Qt.MoveAction)
            event.accept()
        else:
            event.ignore()

    def dropEvent(self, event):
        """Drag and Drop - Drop event"""
        if (event.mimeData().hasFormat("text/plain")):
            text = to_text_string(event.mimeData().text())
            if self.new_input_line:
                self.on_new_line()
            self.insert_text(text, at_end=True)
            self.setFocus()
            event.setDropAction(Qt.MoveAction)
            event.accept()
        else:
            event.ignore()
            
    def drop_pathlist(self, pathlist):
        """Drop path list"""
        raise NotImplementedError


# Example how to debug complex interclass call chains:
#
# from spyderlib.utils.debug import log_methods_calls
# log_methods_calls('log.log', ShellBaseWidget)

class PythonShellWidget(TracebackLinksMixin, ShellBaseWidget,
                        GetHelpMixin):
    """Python shell widget"""
    QT_CLASS = ShellBaseWidget
    INITHISTORY = ['# -*- coding: utf-8 -*-',
                   '# *** Spyder Python Console History Log ***',]
    SEPARATOR = '%s##---(%s)---' % (os.linesep*2, time.ctime())
    go_to_error = Signal(str)
    
    def __init__(self, parent, history_filename, profile=False):
        ShellBaseWidget.__init__(self, parent, history_filename, profile)
        TracebackLinksMixin.__init__(self)
        GetHelpMixin.__init__(self)

        # Local shortcuts
        self.shortcuts = self.create_shortcuts()
    
    def create_shortcuts(self):
        new_shortcut(SHORTCUT_INLINE, self, lambda: self.enter_array_inline())
        new_shortcut(SHORTCUT_TABLE, self, lambda: self.enter_array_table())        
        inspectsc = create_shortcut(self.inspect_current_object,
                                    context='Console',
                                    name='Inspect current object',
                                    parent=self)
        return [inspectsc]
        
    def get_shortcut_data(self):
        """
        Returns shortcut data, a list of tuples (shortcut, text, default)
        shortcut (QShortcut or QAction instance)
        text (string): action/shortcut description
        default (string): default key sequence
        """
        return [sc.data for sc in self.shortcuts]

    #------ Context menu
    def setup_context_menu(self):
        """Reimplements ShellBaseWidget method"""
        ShellBaseWidget.setup_context_menu(self)
        self.copy_without_prompts_action = create_action(self,
                                     _("Copy without prompts"),
                                     icon=ima.icon('copywop'),
                                     triggered=self.copy_without_prompts)
        clear_line_action = create_action(self, _("Clear line"),
                                     QKeySequence(get_shortcut('console',
                                                               'Clear line')),
                                     icon=ima.icon('editdelete'),
                                     tip=_("Clear line"),
                                     triggered=self.clear_line)
        clear_action = create_action(self, _("Clear shell"),
                                     QKeySequence(get_shortcut('console',
                                                               'Clear shell')),
                                     icon=ima.icon('editclear'),
                                     tip=_("Clear shell contents "
                                           "('cls' command)"),
                                     triggered=self.clear_terminal)
        add_actions(self.menu, (self.copy_without_prompts_action,
                    clear_line_action, clear_action))
          
    def contextMenuEvent(self, event):
        """Reimplements ShellBaseWidget method"""
        state = self.has_selected_text()
        self.copy_without_prompts_action.setEnabled(state)
        ShellBaseWidget.contextMenuEvent(self, event)

    @Slot()
    def copy_without_prompts(self):
        """Copy text to clipboard without prompts"""
        text = self.get_selected_text()
        lines = text.split(os.linesep)
        for index, line in enumerate(lines):
            if line.startswith('>>> ') or line.startswith('... '):
                lines[index] = line[4:]
        text = os.linesep.join(lines)
        QApplication.clipboard().setText(text)
    
    
    #------ Key handlers
    def postprocess_keyevent(self, event):
        """Process keypress event"""
        ShellBaseWidget.postprocess_keyevent(self, event)
        if QToolTip.isVisible():
            _event, _text, key, _ctrl, _shift = restore_keyevent(event)
            self.hide_tooltip_if_necessary(key)
                
    def _key_other(self, text):
        """1 character key"""
        if self.is_completion_widget_visible():
            self.completion_text += text
                
    def _key_backspace(self, cursor_position):
        """Action for Backspace key"""
        if self.has_selected_text():
            self.check_selection()
            self.remove_selected_text()
        elif self.current_prompt_pos == cursor_position:
            # Avoid deleting prompt
            return
        elif self.is_cursor_on_last_line():
            self.stdkey_backspace()
            if self.is_completion_widget_visible():
                # Removing only last character because if there was a selection
                # the completion widget would have been canceled
                self.completion_text = self.completion_text[:-1]
                
    def _key_tab(self):
        """Action for TAB key"""
        if self.is_cursor_on_last_line():
            empty_line = not self.get_current_line_to_cursor().strip()
            if empty_line:
                self.stdkey_tab()
            else:
                self.show_code_completion(automatic=False)
                
    def _key_ctrl_space(self):
        """Action for Ctrl+Space"""
        if not self.is_completion_widget_visible():
            self.show_code_completion(automatic=False)
                
    def _key_pageup(self):
        """Action for PageUp key"""
        pass
    
    def _key_pagedown(self):
        """Action for PageDown key"""
        pass
                
    def _key_escape(self):
        """Action for ESCAPE key"""
        if self.is_completion_widget_visible():
            self.hide_completion_widget()

    def _key_question(self, text):
        """Action for '?'"""
        if self.get_current_line_to_cursor():
            last_obj = self.get_last_obj()
            if last_obj and not last_obj.isdigit():
                self.show_object_info(last_obj)
        self.insert_text(text)
        # In case calltip and completion are shown at the same time:
        if self.is_completion_widget_visible():
            self.completion_text += '?'
                
    def _key_parenleft(self, text):
        """Action for '('"""
        self.hide_completion_widget()
        if self.get_current_line_to_cursor():
            last_obj = self.get_last_obj()
            if last_obj and not last_obj.isdigit():
                self.insert_text(text)
                self.show_object_info(last_obj, call=True)
                return
        self.insert_text(text)
        
    def _key_period(self, text):
        """Action for '.'"""
        self.insert_text(text)
        if self.codecompletion_auto:
            # Enable auto-completion only if last token isn't a float
            last_obj = self.get_last_obj()
            if last_obj and not last_obj.isdigit():
                self.show_code_completion(automatic=True)


    #------ Paste
    def paste(self):
        """Reimplemented slot to handle multiline paste action"""
        text = to_text_string(QApplication.clipboard().text())
        if len(text.splitlines()) > 1:
            # Multiline paste
            if self.new_input_line:
                self.on_new_line()
            self.remove_selected_text() # Remove selection, eventually
            end = self.get_current_line_from_cursor()
            lines = self.get_current_line_to_cursor() + text + end
            self.clear_line()
            self.execute_lines(lines)
            self.move_cursor(-len(end))
        else:
            # Standard paste
            ShellBaseWidget.paste(self)
    
  
    #------ Code Completion / Calltips        
    # Methods implemented in child class:
    # (e.g. InternalShell)
    def get_dir(self, objtxt):
        """Return dir(object)"""
        raise NotImplementedError
    def get_module_completion(self, objtxt):
        """Return module completion list associated to object name"""
        pass
    def get_globals_keys(self):
        """Return shell globals() keys"""
        raise NotImplementedError
    def get_cdlistdir(self):
        """Return shell current directory list dir"""
        raise NotImplementedError
    def iscallable(self, objtxt):
        """Is object callable?"""
        raise NotImplementedError
    def get_arglist(self, objtxt):
        """Get func/method argument list"""
        raise NotImplementedError
    def get__doc__(self, objtxt):
        """Get object __doc__"""
        raise NotImplementedError
    def get_doc(self, objtxt):
        """Get object documentation dictionary"""
        raise NotImplementedError
    def get_source(self, objtxt):
        """Get object source"""
        raise NotImplementedError
    def is_defined(self, objtxt, force_import=False):
        """Return True if object is defined"""
        raise NotImplementedError
        
    def show_code_completion(self, automatic):
        """Display a completion list based on the current line"""
        # Note: unicode conversion is needed only for ExternalShellBase
        text = to_text_string(self.get_current_line_to_cursor())
        last_obj = self.get_last_obj()
        
        if not text:
            return

        if text.startswith('import '):
            obj_list = self.get_module_completion(text)
            words = text.split(' ')
            if ',' in words[-1]:
                words = words[-1].split(',')
            self.show_completion_list(obj_list, completion_text=words[-1],
                                      automatic=automatic)
            return
            
        elif text.startswith('from '):
            obj_list = self.get_module_completion(text)
            if obj_list is None:
                return
            words = text.split(' ')
            if '(' in words[-1]:
                words = words[:-2] + words[-1].split('(')
            if ',' in words[-1]:
                words = words[:-2] + words[-1].split(',')
            self.show_completion_list(obj_list, completion_text=words[-1],
                                      automatic=automatic)
            return
        
        obj_dir = self.get_dir(last_obj)
        if last_obj and obj_dir and text.endswith('.'):
            self.show_completion_list(obj_dir, automatic=automatic)
            return
        
        # Builtins and globals
        if not text.endswith('.') and last_obj \
           and re.match(r'[a-zA-Z_0-9]*$', last_obj):
            b_k_g = dir(builtins)+self.get_globals_keys()+keyword.kwlist
            for objname in b_k_g:
                if objname.startswith(last_obj) and objname != last_obj:
                    self.show_completion_list(b_k_g, completion_text=last_obj,
                                              automatic=automatic)
                    return
            else:
                return
        
        # Looking for an incomplete completion
        if last_obj is None:
            last_obj = text
        dot_pos = last_obj.rfind('.')
        if dot_pos != -1:
            if dot_pos == len(last_obj)-1:
                completion_text = ""
            else:
                completion_text = last_obj[dot_pos+1:]
                last_obj = last_obj[:dot_pos]
            completions = self.get_dir(last_obj)
            if completions is not None:
                self.show_completion_list(completions,
                                          completion_text=completion_text,
                                          automatic=automatic)
                return
        
        # Looking for ' or ": filename completion
        q_pos = max([text.rfind("'"), text.rfind('"')])
        if q_pos != -1:
            completions = self.get_cdlistdir()
            if completions:
                self.show_completion_list(completions,
                                          completion_text=text[q_pos+1:],
                                          automatic=automatic)
            return
            
    #------ Drag'n Drop
    def drop_pathlist(self, pathlist):
        """Drop path list"""
        if pathlist:
            files = ["r'%s'" % path for path in pathlist]
            if len(files) == 1:
                text = files[0]
            else:
                text = "[" + ", ".join(files) + "]"
            if self.new_input_line:
                self.on_new_line()
            self.insert_text(text)
            self.setFocus()


class TerminalWidget(ShellBaseWidget):
    """
    Terminal widget
    """
    COM = 'rem' if os.name == 'nt' else '#'
    INITHISTORY = ['%s *** Spyder Terminal History Log ***' % COM, COM,]
    SEPARATOR = '%s%s ---(%s)---' % (os.linesep*2, COM, time.ctime())
    go_to_error = Signal(str)
    
    def __init__(self, parent, history_filename, profile=False):
        ShellBaseWidget.__init__(self, parent, history_filename, profile)
        
    #------ Key handlers
    def _key_other(self, text):
        """1 character key"""
        pass
                
    def _key_backspace(self, cursor_position):
        """Action for Backspace key"""
        if self.has_selected_text():
            self.check_selection()
            self.remove_selected_text()
        elif self.current_prompt_pos == cursor_position:
            # Avoid deleting prompt
            return
        elif self.is_cursor_on_last_line():
            self.stdkey_backspace()
                
    def _key_tab(self):
        """Action for TAB key"""
        if self.is_cursor_on_last_line():
            self.stdkey_tab()
                
    def _key_ctrl_space(self):
        """Action for Ctrl+Space"""
        pass
                
    def _key_escape(self):
        """Action for ESCAPE key"""
        self.clear_line()
                
    def _key_question(self, text):
        """Action for '?'"""
        self.insert_text(text)
                
    def _key_parenleft(self, text):
        """Action for '('"""
        self.insert_text(text)
        
    def _key_period(self, text):
        """Action for '.'"""
        self.insert_text(text)
            
            
    #------ Drag'n Drop
    def drop_pathlist(self, pathlist):
        """Drop path list"""
        if pathlist:
            files = ['"%s"' % path for path in pathlist]
            if len(files) == 1:
                text = files[0]
            else:
                text = " ".join(files)
            if self.new_input_line:
                self.on_new_line()
            self.insert_text(text)
            self.setFocus()
